Continuously cast workpieces, in particular slabs, are mostly subjected after continuous casting to a surface treatment by grinding so as to achieve a sufficient quality during the subsequent processing of the product. When grinding continuously cast slabs, the slab is usually reciprocated back and forth under a grinder (grinding aggregate) in the longitudinal direction. At the end of each reciprocation, the grinder carries is indexed transversely until the entire slab surface is ground.
During grinding, the slab is mounted on a grinding table and rests on its wide face or broad side.
A generic, known apparatus for grinding slabs is shown in FIGS. 1 to 3. The apparatus is similar to the one described in EP 0 053 274.
In the apparatus according to FIG. 1, so-called HP grinding (High-Pressure Grinding) is carried out. The apparatus has a grinding table 6 and a grinder 21 in the form of a main aggregate with drive motor and grinding wheel 7. In a known manner, the slab 1 has two wide faces 2 and 3 (broad sides) and two narrow faces 4 and 5 (narrow sides). The slab rests with one of its wide faces 3 on the grinding table 6. During grinding of the upper face of the slab, the grinding table 6 is reciprocated under the grinder 21 in a direction perpendicular to the view plane. Here, the grinding wheel 7 is pressed by a grinding pressure cylinder 14′ against the upper side of the slab 1. Thus, the slab 1 is reciprocated longitudinally by the grinding table 6 relative to the grinder 21. After each reciprocation, the grinder 21 is indexed transversely by a feed cylinder 22 until the entire upper side of the slab is finish-ground.
Depending on quality requirements it is necessary here to grind not only the wide slab faces 2 and 3 but also the narrow slab faces 4 and 5. Therefore, in addition to the grinder 21, that is the main aggregate, for grinding the wide faces 2 and 3 of the slab 1, there is a second grinder 23 in the form of an auxiliary aggregate intended to grind the narrow faces 4 and 5 of the slab 1. Here too, a grinding wheel 7 is provided.
After the upper wide face 2 of the slab has been ground by the main aggregate 21, a narrow face 5 of the slab 1 is ground by the auxiliary aggregate 23.
FIGS. 2 and 3 respectively illustrate the main aggregate 21 and the auxiliary aggregate 23, the movement of the grinding wheel 7 during grinding, i.e. the feed by the aggregates 21, 23 being indicated insofar that the grinding wheel and its spindle is shown in each case in two different positions. The expenditures associated with the additional installation of an auxiliary aggregate are relatively high.
Moreover, one problem is that severe caking of grinding chips on the apparatus can occur if the path of flying chips cannot be optimized. Thus, in case of the known solutions, high maintenance expenditures are required.